Casing shoe



D. D. BURCHI CASING SHOE Filed Feb. 25. 1926 Ak ////////f141 Patented Unt. 19, 1926..

UNITED STATES PATENT OFFICE.

DONALD D. BURCH, 0F EL DORADO, ARKANSAS.

This invention relates casing shoes and more particularly to a casing shoe intended for use in connection with well casings which are to be cemented in position or which, because of their weight, must have a portion of the weight floatedV as they are lowered into the well.

important object of the inventlon. 1s to provide a device of this character which may be relatively cheaply constructed and which may be readily attached to the casgA further and more specific object of the invention is to provide means for plugging the shoe whereby liquids or semi-liquids may be forced from the interior of the shoe to the exterior the-reof so that they will arise about the casing, but these liquids may not return to the interior of the shoe.

These and other objects I attain by the construction shown in` the accompanying drawing, wherein for the purpose of illustration is shown a preferred embodiment of my invention and wherein Figure 1 is a vertical sectional view through a casing shoe constructed in accordance with my invention showin the same in position upon the bottom o the well' Figure 2 is a similar section showing the effect of introduction of cement and the plug for sealing the ports 12;

Figure 3 is a section on the linel 3-3 of Figure 1.

Referring now more particularly to the drawings, the numeral 1() indicates a casing shoe adapted to be engaged with the lower end of a casing 11 and having in the walls thereof vertically extending ports 12, the upper ends of which open through the inner wall of the casing shoe at the upper and lower ends thereof, as at 13 and 14. Intermediate the upper and lower ends of the ports 12, the walls of the shoe have formed therethrough other ports 15 which are circumferentially spaced from the ports 12.

A plug 16 is provided having a longitudinal bore 17 terminating at its lower end short of the lower end of the plug and at its upper end opening through the upper HEISSUED end of the plug. Adjacent its lower end, the bore is reduced to provide an upwardly facing valve seat 18 for a ball valve 19. The upper end of the bore is sealed by a plug 20. rIhe outer face of the bore is provided with vertically spaced circumferential grooves 21, 22, the groove 21 being connected by ports 23 with the bore 17 intermediate the plug 20 and the seat 18 while the groove 22 is connected by ports 24 with the lower end of the bore 17. The grooves 21 and 22 are spaced apart a distance equal to the spacing between the ports y15 and the lower end 14 of the ports 12. The exterior of the plug 16 and the interior of the shoe have coacting screw-threads 25. When the plug is properly seated, the grooves 21, 22 align with the ports 15 and the ends 14 of the ports 12.

It will be obvious that when a casing having a shoe provided with a plug of this character is lowered into the well, fluids Within the well cannot enter the casing for the reason that these fluids, as they enter through the ports 15, grooves 21 and ports 23 will exert a pressure, forcing the valve 19 into position upon its seat. Therefore, the plug serves to seal against the admis- `sion of fluids to the lower end of the casing and the casing may be lowered into the well and partially supported by the buoyancy of its submerged portion. If this buoyancy increases to too great an extent, it may be counteracted by admitting water or other material to the interior of the casing from the upper end thereof. Where the casing, after arriving in proper position, is to be cemented, the fluid inserted to counteract the buoyancy would, of course, be the cement which must be employed. In cementing a well, the casing is lowered into position, the desired amount of cement placed in the casing and a follower plug 26 placed on top of the cement. Pump pressure is then exerted against the follower plug 26 with the result that this plug moves downwardly in the casing, forcing the cement before it through the ports 12 to the grooves 22 and ports 24, displacing the valve 19 so that the cement may pass through the ports 23, grooves 21, ports 15 to the exterior of the casing. When the plug 26 arrives at the lower end of its travel, it will cover the upper ends 13 of the ports 12, sealing the same and giving notice by the increased resistance to operation of the pump that the cement has been completely removed. Pump pressure may then be entirely removed and the check ball 19 will effectually prevent return of the cement to the casing. 'Ihe plug 16 is preferably formed of some readily displaceable material such as lead and the plug 26 is similarly formed so that these plugs may be drilled out of the casing after 4the cement has set.

Since the construction hereinbefore set forth is capable ot a certain range of change and modification without materially departing from the spirit of the invention, I do not limit myself to such specific structure except as hereinafter claimed.

I claim 1. A casing shoe for the purpose described having a plug tted in the lower end thereof, the plug having a bore provided int-ermediate its ends with a valve seat, the ends of the bore being sealed, a valve for coaction with said seat, ports opening through the wall of the shoe and communicating with said bore at one side of the valve and ports connecting the interior of the shoe above the plug with the bore at the opposite s ide of the valve.

2. A casing shoe for the purpose described having a' plug fitted in the lower end thereof, the plug having a bore provided intermediate its ends with a valve seat, the ends of the bore being sealed, a valve for coaction with said seat, ports opening through the wall of the shoe and communicating with said bore at one side of the valve, ports connecting the interior of the shoe above the plug with the bore at the opposite side oi the valve and a second plug tting the bore of the shoe and when supported from the first named plug sealing the ends of the last named ports which communicate with the interior of the shoe.

3. A casing shoe for the purpose described having a plug litted in the lower end thereof, the plug having a bore provided intermediate its ends with a valve seat, the ends of the bore being sealed, a valve for coaction with said seat, ports opening through the wall of the shoe and communicating with said bore at one side of the valve, and ports connecting the interior of the shoe above the plug with the bore at the opposite side of the valve, said plug being of sott metal.

4. ln combination with a casing shoe, a plug tted in the lower end of the shoe, said plug having a longitudinal bore sealed at its upper and lower ends, the bore being provided intermediate its ends with an upwardly facing valve seat and a valve coacting with said seat, the periphery oit' the plug having channels formed therein, ports connecting one of said channels with the bore above and the other of the channels with the bore below the valve seat, ports extending through the side wall of the shoe and communicating with the first named channel and ports in the wall of the shoe communicating at their lower ends with the last named channel and at their up r ends with the interior of the shoe above t e plug.

5. In combination with a, casing shoe, a plug fitted in the lower end of the shoe, said plug having a longitudinal bore sealed at its upper and lower ends, the bore being provided intermediateits ends with an upwardly facing valve seat and a valve coacting with said seat, the periphery of the plug having'channels formed therein, ports connecting one of said channels with the bore above and the other of the channels with the bore below the valve seat, ports extending through the side wall of the shoe and communicating with the first named channel, ports in the wall of the shoe communicati at their lower ends with the last name channel and at their upper ends with the inf terior of the shoe above the plug and a sec ond 'plug of substantially the same diameter as the internal diameter of the shoe and of a length greater than the dist-ance between the upper end of the first named lng and the upper ends of the last nainedpports.

6. In combination with a casing shoe. a plug fitted in the lower endozt the shoe, said plug having a longitudinal bore sealed at its upper and lower ends, the bore being provided intermediate its ends with an npwardly Jfacing valve seat and a valve coacting with said seat, the periphery oit the plug having channels formed therein, ports connecting one ot said channels with the bore above and the other ot the channels with the bore below the valve seats, ports extending through the side wall of the shoe and communicating with the first named channel, ports inthe wall of the shoe communicating at their lower ends with the last named channel and at their upper ends with the interior ot the shoe above the plug and second plug of substantially the same diameter as the internal diameter of the shoe and of a length greater than the distance be tween the upper end ot the first named plug and the upper ends of the last named ports, said plugs being of soit metal removable from the shoe by drilling.

7. ln combination with a Casin shoe, a plug iitted in the lower end of the s oe, said plug having a longitudinal bore sealed at its upper and lower ends, the bore being proq vided intermediate its ends with an upwardly tacing valve seat and a, valve (reacting with said seat, the periphery of the plug having channels formed therein, ports connecting one of said channels with the bore mower above and the other of the channels with the terior of the shoe ehove the plug, sold plug here below the Valve seat, ports extending heilug el' soft meml removable from the shoe through the side woll of the shoe and eom-4 hy drilling. l@ .municotimg with the rst named channel and In testimony whereof hereunto e my ports in the Well of the shoe in; unicetin signesure.

et their lower ends with the last name chermel and et their upper ends with the m K DON D. BURGER 

